1. Field of the Invention
The present invention relates to a method and an apparatus usable in network external storage, and more particularly to a method and an apparatus usable in Network Attached Storage (NAS).
2. Related Art
As information technology develops and encompasses new, multimedia applications, the amount of data moving between different system platforms increases geometrically. Conventional network storage structures using servers as main memory devices cannot cope with data streams so large. Therefore, a new pattern of data storage, independent from the storage devices it relies on, which can provide good expandability, availability and reliability, is desired. To meet this need, the Network Attached Storage (NAS) pattern was invented and generally uses a plurality of hard disk drives (HDDs) as external storage devices.
An HDD comprises a storage medium, e.g., a hard disk, a read/write head, a spindle motor that rotates the storage medium, and a circuit board. The circuit board includes a connector to connect the HDD to an interface board of a computer system. The Integrated Device Electronics (IDE) interface is a defacto standard interface for connecting HDDs to computer systems. An HDD that conforms to the IDE standard will be referred to as an “IDE_HDD”. Currently, HDDs used in NAS are normally IDE_HDDs. The IDE standard allows two IDE_HDDs to connect to a single interface board to form an IDE channel, wherein one is generally called “master” and the other is called “slave”. The interface board provides two ports for connecting two HDDs respectively. When two HDDs are installed, one HDD serves as a master HDD while the other serves as a slave HDD.
However, if eight IDE_HDDs are installed in the system, the peak starting current during boot-up can be up to 16A, since all the IDE_HDDs spin up together at the same time. A conventional power supply cannot endure so high a peak current and power consumption, and can easily burn out. A special power supply to supply the needed power increases the cost of the system. A control apparatus is desired to control the IDE devices to sequentially spin up using different assigned identification (ID) numbers. Accordingly, a method and a corresponding apparatus for assigning ID numbers to the IDE devices for use in such control apparatus is desirable.